Dec. 27 (Bloomberg) -- U.S. prosecutors can keep computer records seized from Major League Baseball's drug testing administrator as part of an investigation into player use of illegal steroids, a federal appeals court ruled.

The U.S. Court of Appeals in San Francisco today held that lower courts were wrong to require government investigators to return files taken from the Bay Area Laboratory Co-Operative, a Burlingame, California, lab known as Balco.

The files sought by prosecutors were seized in 2004 while investigating 10 unidentified athletes during the Balco probe. The Major League Baseball Players Association fought the government's request for the documents, arguing the seizure violated the players' constitutional right against unreasonable searches and seizures.

``We conclude that the government's seizures were reasonable,'' a three-judge panel wrote in an opinion. Evidence gathered by investigators that isn't related to players named in search warrants must be returned, the panel ruled.

Elliot Peters, a lawyer for the players association, didn't immediately return a call seeking comment.

The case is In Re: Search Warrants, 05-10067, 9th U.S. Circuit Court of Appeals, San Francisco.

To contact the reporter on this story: Joel Rosenblatt in San Francisco at rosenblatt@bloomberg.net.

Last Updated: December 27, 2006 14:31 EST